This invention relates to an element selecting device having a function capable of selecting one of a plurality of optical elements, such as optical filters, and locating it at a predetermined position in an optical path, and more particularly to an element selecting device arranged so as to be smoothly moved in a predetermined plane having a positional relationship with the optical path.
An image processing device is known which makes copies by employing a so-called electrophotographic system. In an image processing device such as an image scanner, reflected light from an original irradiated by an illuminating optical system focuses an image on a light receiving element such as a CCD (Charge Coupled Device) sensor through a reduction optical system. The optical image corresponding to the image of the original is converted into a series of electrical image signals.
On the other hand, in a color image processing device, the reflected light from the original is focused on the light receiving element through color separation filters respectively corresponding to a particular color, and then, a plurality of optical images each corresponding to these colors are converted to a series of electrical image signals.
Generally, the above color image processing device is arranged to read the image signals corresponding to three primary colors, i.e. red(R), green(G), and blue(B); and to selectively locate one of three kinds of filters in an optical path of the reflecting light from the original. An image is realized on the light receiving element according to the located filter. An ND filter also is employed as well as three color filters for regulating an optical length and amount of light. Therefore, four kinds of filters are selectively inserted in the optical path.
A filter conversion device which selectively inserts one of a plurality of filters into the optical path has been suggested in various types of mechanical systems. For example, there is a filter conversion device which has a disk plate capable of being transversely revolved having a plurality of round holes thereon, each of the holes are formed at positions at which a predetermined consentient circle is equally divided, and round-shaped filters are engaged in the holes, respectively. When the disk plate is revolved around the shaft, the surface of the filters are transverse and perpendicular to the axis of the optical path.
In the color image processing device, a minimization of the device has been recently required and therefore, element selecting devices of a small size are needed. Since the element selecting device using the rotatable disk plate requires a container with a height equivalent to the length of a diameter of the disk, it has been difficult to construct the compact equipment employing the element selecting device described above.